270 Hammer Love

[Northkill]

I get beat up a lot. Trying to be conservative!

Yep kinda figured. You'd expect it to be a tad better than the 156 in the same rifle though I'd assume?

 

[Muddyboots]

So at 8K it looks like it will be ok if I were to hunt elevation with 1:8tw. Guessing or hoping on velocity based upon the 156. Prob little lower. Look about right?

 

[RockyMtnMT]

So at 8K it looks like it will be ok if I were to hunt elevation with 1:8tw. Guessing or hoping on velocity based upon the 156. Prob little lower. Look about right?
View attachment 332087View attachment 332088

Here is what we have learned. The elevation helps with ballistic stability. I doesn't seem to help with terminal stability. This seems to be much more dependent on rpm's. Also the longer the bullets are for caliber the more critical there stability gets. So when we calculate minimum required twist we do so at standard atmosphere at sea level showing a 1.5 sg. If we stay pretty hard with this then there is very little issue with on game performance.

This bullet is starting to push the threshold of bullet length to caliber ratio. The point that everything just comes undone is about 6 times caliber in length. This bullet is only .082" from that ratio.

 

[Muddyboots]

Steve,
Thx, good stuff, guess I will stay with the 156.

 

[Muddyboots]

Maybe another thread to discuss the effect of elevation on SG where marginal at low but good at higher versus terminal stability? I searched site and really didn't find much.

Somebody got a good read to link?

 

[RockyMtnMT]

Maybe another thread to discuss the effect of elevation on SG where marginal at low but good at higher versus terminal stability? I searched site and really didn't find much.

Somebody got a good read to link?

I know I have posted about it several times in the past. I don't recall a thread about it though.

 

[Muddyboots]

Steve,
Found a couple threads now that I have better search criteria. Thx!

Powder Selection

Why change bullets? If you're getting good results with the 139sst, what does changing to the 150eldx do for you? 139 G1 = .486 150 G1 = .574 For the sake of conversation, I ran the ballistics for each bullet using JBM Ballistics. Using 300fps for the 139 and 2850 for the 150. Using this data...

www.longrangehunting.com

Post in thread 'Optimal/ ideal stability factor?'
https://www.longrangehunting.com/threads/optimal-ideal-stability-factor.213379/post-1548597

Thread 'Optimal/ ideal stability factor?'
https://www.longrangehunting.com/threads/optimal-ideal-stability-factor.213379/

 

[Alibiiv]

These should work pretty nicely in a fast twist .270 also...

270 Caliber 170 Grain Extreme Outer Limits (EOL) Elite Hunter Rifle Bullet

EOL Elite Hunters were developed through a partnership with Berger and Extreme Outer Limits TV. Elite Hunter Bullets are identical in construction, shape and performance to the Berger Hybrid Target series, except they utilize a thinner J4 Precision Jacket for rapid expansion on game animals.

bergerbullets.com

Would you please define "fast twist" as it was used in this reply????

 

[adam32+P]

Would you please define "fast twist" as it was used in this reply????

Anything faster than the standard 1/10.

 

[RockyMtnMT]

Would you please define "fast twist" as it was used in this reply????

I think Berger lists min twist rates now. Would be best to look at their site to know for sure what twist is considered fast enough.

 

[jpfrog]

I kill me!! I wasn't sure if anyone would catch it!

Been a long day I guess…what did I miss?

 

[RockyMtnMT]

Been a long day I guess…what did I miss?

It's a love hate thing!

 

[jpfrog]

It's a love hate thing!

I figured it had to do with that.

Joking aside, these 162s look nice. Wish my 10 twist was faster so I could try them, but I have a bunch of 117s sitting around that it likes to be fed for now